Recently, the world of badminton was faced with the daunting possibility that one of the world's greatest players, Taufik Hidayat, might change loyalties from Indonesia to Singapore.

Had it happened, he would have become favourite for the men's singles gold medal at the Commonwealth Games and targets which affect funding for the sport would have been seriously jeopardised.

It would have also led to a strong argument for selecting three former world number one men's doubles players from Indonesia, Rexy Mainaky, Flandy Limpele, and Eng Hian - all sparring partners for the English national squad, their country of domicile.

"It will be like a bomb under our programme," English badminton performance director Finn Traerup said at the time.

Fortunately, the bomb did not go off, mostly as a result of some canny diplomacy by the International Badminton Federation (IBF) which reconnected Taufik with his national association.

Scotland's Peter Nicol will compete for England at the Games

However, the issue of who plays for which country and why, remains controversial, even potentially explosive, within all three indoor racquet sports.

Singapore may field three badminton players at the Commonwealth Games who have come from Indonesia, and Hong Kong could have one, in addition to their former world women's singles quarter-finalist Wang Chen, who crossed the border from China to the former British colony.

Several other countries have in the past fielded outstanding players whose formative years were spent elsewhere.

One of the most conspicuous is table tennis player Geng Lijuan, the former world number one from China who has for more than a decade represented Canada.

Few now challenge the validity Geng's transfer of loyalties, or that of another table tennis medal contender Johnny Huang, who made the same transcontinental cross-cultural upheaval.

But there have been others whose motives have been questioned, such as world squash champion Peter Nicol.

The Scot already held a British passport and became English quite simply and quickly on the basis of a two-year residential qualification.

He will be favourite to win gold medals at successive Games, but for different countries.

Nicol's principle reason for the change is the better coaching, medical and other back-up facilities available with another national association, which will increase the chances of prolonging his career at the highest level.

Such enterprise is understandable according to professional logic, but is it within the spirit of "the friendly Games"?

Mass migration

Other defections have been made with transparently short-term commercial motives.

During the 1990s, the International Table Tennis Federation was forced to toughen its eligibility rules after an exodus of more than 300 table tennis players and coaches from China.

The IBF has been slower to tighten its rules, and the changes made in May - players switching countries now need a passport and a three-year interval, not two years - come too late to influence selection for the Commonwealth Games.

For this, it has been criticised but movement between countries is increasing all the time and may continue to grow.

Ideas about identity, or of multiple identities, are gradually changing and boundaries, perhaps even principles, may gradually become blurred.

Today's controversial opportunist could become regarded as tomorrow's welcome cosmopolitan.